Tilting-boom log-handling crane



Feb. 4, 1964 K. E. ROBERTS ETAL 3,120,310

TILTING-BOOM LOG-PANDLING CRANE Filed May 20. 1960 2 Sheets-Sheet 1JNVENTORSkrS ew 6, P055 3% M. P085975 Y WMZM Feb. 4, 1964 K. E. ROBERTSETAL 3,120,310

' TILTING-BOOM LOG-HANDLING CRANE Filed May 20, 1960 2 Sheets-Sheet 2 l8i b, /9 25 Z INVENTORS. Z x z/vlv'r/l Baa-P75 BY At my M. P0362725 W m42 my.

United States Patent 3,126,310 TILTING-BOQM LGG-HANDLING (IRANE KennethE. Roberts, Box 2%, Montesano, Wash, and Alvin M. Roberts, Brooldyn,Wash. Filed May 20, 19%, Ser. No. 30,522 3 Claims. (Cl. 2l2-- i2.5)

This invention relates to a crane intended primarily for piling andunpiling and for loading logs onto a truck in the woods.

For this purpose, it is a principal object to provide such alog-handling crane which can be operated more quickly than aconventional type of crane and which will have better control over logsbeing hoisted, particuledly for swinging them sidewise and for shiftingthem lengthwise. An incidental object is to be able to grab a logeffectively nearer one end than the other instead of it being necessaryto support the log at its center or at locations spaced a substantialdistance apart lengthwise of the log.

Another object is to provide such a crane which can grab a logautomatically without requiring a workman to set a line or sling aroundthe log.

Such a crane also is compact and readily mobile to facilitate its use.

These objects and advantages can be accomplished by a crane having aboom tiltably supported on the upper end of a mast, which boom has apair of log-gripping tongs pivotally mounted on its hoisting end and alogengaging abutment located between such tongs and the crane mast. Thecrane is rigged to control both the inclina ion of the mast and the tiltof the boom relative to the mast for the purpose of hoisting logs,shifting them lengthwise and lowering them, and the mast and boomassembly are further mounted on a turntable for conjoint swinging abouta vertical axis.

FIGURE 1 is a top perspective view of the crane.

FIGURE 2 is a plan view or" the crane.

FIGURE 3 is a side elevation view of the crane with parts broken away.

FIGURE 4 is a front elevation view of the crane.

FIGURE 5 is a fragmentary side elevation view of a portion of the mastand boom in a relationship difierent from that shown in HGU'RE 3.

FIGURE 6 is a fragmentary side elevation view of the hoisting endportion of the boom shown converted for use as a shovel, and PlGUR-E 7is a similar view shown converted for use as a hoe.

In the drawings, the chassis of the hoist is shown diagrammatically, itbeing understood that suitable cab and control mechanism of conventionalcharacter would be provided for the crane. Such crane is mounted on aturntable 1 which preferably is supported on a mobile chassis which issupported on and self-propelled by endless tracks 2. The hoistingoperation is effected and contro led by suitably driving two cable drums3 and 4 by suitable power mechanism of conventional type, which is notshown. The control mechanism would eiiect rotation of either drum ineither direction independently of the other so that the drums could beoperated either separately or simultaneously at any desired speed andcould be held in any desired position by suitable bra-1e mechanism.Ordinarily it will be necessary to provide power mechanism for suchdrums only to drive them in a winding direction and to control payingout of the lines in the unwinding direction.

On the turntable 1 is swingably supported the mast 5 mounted on ahorizontal pivot 6. The upper portion of this mast carries a pivot 7 onwmch the boom 8 composed of two spaced apart parallel spars 9 ismounted. These spars preferably are spaced apart sufficiently to receivebetween them the upper end portion of the mast 5, as sh wn best inFIGURES l, 2 and 4. The pivot 7 should be located closer to the heel endof the boom than to its hoisting end and the spars are connectedadjacent to their heel ends by a shaft it and preferably also by a cleat11. The hoisting end portions of these spars are interconnected by ashaft 12 which serves as a pivotal support for log-engaging tongs 13movable between open and closed positions in a plane parallel to theaxis of the pivot defined by shaft 12. In addition, these spa-rs areinterconnected by an abutment 14 located between the tongs 13 and themast 5.

Both the degree of inclination of the mast 5 and the angle of tilt ofthe boom 8 relative to the mast can be controlled by two lines wound ondrums 3 and 4 which are connected to the boom 8 at opposite sides of thepivot 7 connecting the mast and boom, as shown in FIGURES 1 and 3. Thusthe inclination of the mast is controlled by varying appropriately theeffective length of the control lines either separately or conjointlyand such swinging of the mast usually is accompanied by swinging of theboom relative to the mast. The load tending to tip the mast downwardlyis resisted primarily by the line connected to the boom between the mastand the hoisting end of the boom and such resisting force can be appliedm re effectively by rigging this line to react from an anchor frame 15upstanding from the turntable 1. This frame is composed of posts 16connected by a cross bar 17 and supported by inclined brace struts 18. i

The line 19, acting principally to resist the tendency of a load on theboom to tilt the mast 5 downward, is wound on the drum 3 on turntable 1and extends from such drum upward over sheave 2% on the cross bar 17 ofthe anchor frame, then around a sheave 21 journaled on one spar 9, backaround two sheaves 22 journaled in a yoke 23 swingable on the cross bar17 to maintain the stretches of the line engaging such sheaves in spacedrelationship, out again around the other sheave 21 on the other spar 9and back to a line end securing anchor 24 on the portion of the anchorframe 15 remote from the sheave 2G.

The tilt of the boom 8 relative to the mast 5 is controlled also by theother line 25 which is wound on the drum 4 and extends from such drum toa sheave 26 carried by the heel portion of the boom overhanging beyondthe mast pivot 7, then down around a sheave 27 mounted on the lowerportion of the mast 5, upward again around a second sheave 26 carried bythe heel overhang of the boom and down again to an anchor 28 shown asbeing on the anchor frame 15 but which could, if desired, be on theturntable such as adjacent to the drum 3. It will be noted in FIGURES 1and 2 that, with the exception of the standing end portion of the line25, all the stretches of such line are located between the stretches ofthe line 19 engaging the sheaves 22 which are held apart by the spacedlocations of such sheaves, as described above. The standing end portionof line 25 may also extend between such stretches of the line 19, ifdesired.

In use, to hoist a log line 2'5 will be paid out to dispose the boom gin a generally upright position and then both lines w and 25 may be paidout simultaneously to enable the mast 5 and boom 8 to swing down-wardconjointly until the log-engaging tongs 13 engage the side of a log.Further conjoint lowering of the mast and boom will cause the log towedge the tongs open so that they will be engaged around a log and willbe closed on it by the weight or" the tongs arms. if the lines 1 and 25are then reeled in, the log will be hoisted because the weight of thelog will tend to maintain the tongs arms closed. If the tongs areengaged with the log at its center of gravity, the log will be lifted ina horizontal position as illustrated in FIGURE 3. Also, if it is desiredto shift the log lengthwise away from the crane, the line 25 will bereeled in to tilt the boom 8 upward toward horizontal position, as shownin FIGURE 3.

With the log thus hoisted, the turntable 1 may be rotated in onedirection or the other to a location where it is desired to deposit thelog, and if it is desired to shift the log still further outwardlengthwise from the crane, line 25 can be reeled in and line 19 paid outto effect such shifting of the log at the same time that it is lowered.While the turntable 1 is being swung, the log L gripped by the tongs canbe maintained parallel to a vertical plane substantially parallel to themast 5 and boom 8 by engaging the log with abutment 14 although thetongs 13 are mounted to swivel about the horizontal axis of pivot 12 andalso are mounted for swivelling about an axis perpendicular to the axisof pivot 12. Much better control over the log L is maintained than if itwere on the end of a hoisting line. The log has little tendency todepart from a vertical plane parallel to mast 5 and boom 8, even whenmast 5 is swung by rotation of the turntable. The log can be swungend-for-end in controlled fashion by dragging one end of the log as themast is swung by the turntable. To deposit the log after it is lowered,it is merely necessary for the tongs to be lowered so that the arms willswing open and the bottom is moved lengthwise of the log to drag thetongs onto the log in closed condition. The boom can then be swung toslide the tongs oil the log.

The crane may have a reach which is too short to enable the tongs 13 tobe engaged at the center of gravity of the log. In that case, the tongscan be engaged with a portion of the log closer to the end adjacent tothe crane, as shown in FIGURE 5. As the line is reeled into hoist thelog either conjointly with or independently of line 19, the end of thelog adjacent to the crane will be raised above the opposite end of thelog until the end portion of the log adjacent to the crane engages theabutment 14, as shown in FIGURE 5. Thereafter, the log will be lifted ina position substantially parallel to the boom 8. Thus supported, the logcan be moved sidewise by rotation of the turntable 1 and movedlengthwise in one direction by reeling in line '19 to swing the mast 5toward the vertical position or paying out line 19 while reeling in line25 to swing the mast farther toward horizontal position.

When the log has been shifted approximately to the desired positionwhere it is to be deposited, line 19 can be paid out somewhat while line25 is paid out to a greater extent so that the lengthwise position ofthe log will not be shifted appreciably while the boom 8 is being tilteddownward to deposit the log. When the ton-gs 13 have been relieved ofthe weight of the log, they may be released from'the log as describedpreviously.

While the operation of the crane has been described above in connectionwith the operation of handling logs, it is possible to convert the craneso that it will hoist dirt by converting the crane into a scoop shovelas shown in FIGURE 6, or into a backhoe as shown in FIGURE 7. To efiectsuch conversion, it is merely necessary to re place the tongs 13suspended from the end of the boom 8 by a scoop shovel head29 having adumping door 30 released by a trip line 31, or by substituting thebackhoe head 32, shown in FIGURE 7, on the end of the boom 8. The samerigging described for operation of the crane can be used to manipulatethe boom '8 for digging with and dumping either the shovel or the hoe.

In manipulating the shovel head 29, the line 19 would be reeled in andthe line 25 paid out until the hoisting endof the boom 8 has been swungtoward the mast 5 beyond vertical and such mast has been loweredsufficiently to enable the digging edge 33 of the scoop shovel tocontact the ground. Thereupon, the line 2-5 will be reeled in to swingthe boom 8 upward toward the position of FIGURE 6. Next the turntable 1can be rotated and the position of the scoop shovel head adjusted byappro priate swinging of the boom and toast 5 to a desired location fordumping the dirt and .thedirt can then be dumped by pulling on the tripline 31 to release the door 30. As the shovel head is swung into aposition to take another scoop of dirt in the manner described, theforce of gravity acting on the door 39 will automatically engage thelatch again so that the scoop shovel can be refilled.

To use the hoe head 32, both lines 19 and 25 will be paid out to swingthe mast 5 downward while the boom 8 is maintained inclined downwardslightly until the digging edge 34 is engaged with the ground.Thereupon, line 19 will be reeled in while line 25 is paid out to swingthe boom 8 toward vertical position to enable the backhoe head 32 toexecute a scooping action. When the hoe head has thus been filled withdirt, line 19' will con tinue to be reeled in while line 25 will be paidout to raise the hoe above the ground. The mast can then be swung byrotation of the turntable 1 to a location for dumping the dirt and theline 25 can then be reeled in to swing the hoisting end of the boomupward for dumping the dirt from the hoe head. The digging operation canthen be repeated in this manner.

We claim as our invention:

1. A tilting boom crane comprising a base, a mast, mast pivot meanssupporting said mast on said base for swinging about a substantiallyhorizontal axis, a boom, boom pivot means located between the ends ofsaid boom and tiltably supporting said boom on the upper portion of saidmast, load-supporting means carried by said boom at one side of saidboom pivot means, and rigging operable to apply force for swinging saidmast relative to said base and for tilting said boom relative to saidmast, said rigging including a sheave mounted on the lower portion ofsaid mast, a first line connected to said boom at a location betweensaid boom pivot means and said loadsupporting means, a second lineconnected to a portion of said boom at the side of said boom pivot meansremote from said load-supporting means and located a distance from saidboom pivot means greater than the distance between the connection ofsaid first line to said boom and said boom pivot means, and said secondline being looped from its connection to said boom downward around saidsheave, and means operable to vary the effective lengths of said lines,for tilting said boom rela tive to said mast principally by varying theeffective length of said second line and for swinging said mast relativeto said base principally by varying the eifective length of said firstline.

2. A tilting boom crane comprising a base, a mast, mast pivot meanssupporting said mast on said base for swinging about a substantiallyhorizontal axis, a broom, boom pivot means located between the ends ofsaid boom and tiltably supporting said boom and the upper portion ofsaid mast, load-supporting means carried by said boom at one side ofsaid boom pivot means, a sheave mounted on the lower portion of saidmast, boom-tiltingline-engaging means on said boom at the side of saidboom pivot means opposite said load-supporting means, linelength-varying means carried by said base and located a distance from.

said mast pivot means approximately equal to the distance of saidboom-tilting line-engaging means from said boom pivot means,boom-tilting line means interconnectmeans to effect principally tiltingof said boom relative to said mast, and mast-swinging line meansconnected to a portion of said boom between said load-supporting meansand said boom pivot means, disposed adjacent to said boom pivot meansand variable in effective length to 5 effect principally swinging ofsaid mast relative to said base.

3. A tilting boom crane comprising a base, a mast, mast pivot meanssupporting said mast on said base for swinging about a substantiailyhorizontal axis, a boom, boom pivot means located between the ends ofsaid boom and tiltably supporting said boom on the upper portion of saidmast, load-supporting means carried by said boom at one side of saidboom pivot means, and rigging operable to apply force for swinging saidmast relative to said base and for tilting said boom relative to saidmast, said rigging including first lineholding means, a first lineextending, independently of said mast, directly between said firstline-holding means and a location on said boom between said boom pivotmeans and said loadsupporting means, second line-holding means lowerthan said first line-holding means, a second line crossing said firstline and extending between said second line-holding means and a portionof said boom at the side of said boom pivot means remote from saidload-supporting means and spaced from said boom pivot means a distanceconsiderably greater than the distance between said boom pivot means andthe location on said boom to which said first line extends, and meansoperable to vary the eflective lengths of said lines, for tilting saidboom relative to said mast principally by varying the efiective lengthof said second line and for swinging said mast relative to said baseprincipally by varying the effective length of said first line.

References Cited in the file of this patent UNITED STATES PATENTS1,884,861 Remde Oct. 25, 1932 2,930,045 Billings Feb. 11, 1936 2,303,852Linn Dec. 1, 1942 2,595,864 Lawry May 6, 1952 2,656,059 Troyer Oct. 20,1953

1. A TILTING BOOM CRANE COMPRISING A BASE, A MAST, MAST PIVOT MEANSSUPPORTING SAID MAST ON SAID BASE FOR SWINGING ABOUT A SUBSTANTIALLYHORIZONTAL AXIS, A BOOM BOOM PIVOT MEANS LOCATED BETWEEN THE ENDS OFSAID BOOM AND TILTABLY SUPPORTING SAID BOOM ON THE UPPER PORTION OF SAIDMAST, LOAD-SUPPORTING MEANS CARRIED BY SAID BOOM AT ONE SIDE OF SAIDBOOM PIVOT MEANS, AND RIGGING OPERABLE TO APPLY FORCE FOR SWINGING SAIDMAST RELATIVE TO SAID BASE AND FOR TILTING SAID BOOM RELATIVE TO SAIDMAST, SAID RIGGING INCLUDING A SHEAVE MOUNTED ON THE LOWER PORTION OFSAID MAST, A FIRST LINE CONNECTED TO SAID BOOM AT A LOCATION BETWEENSAID BOOM PIVOT MEANS AND SAID LOADSUPPORTING MEANS, A SECOND LINECONNECTED TO A PORTION OF SAID BOOM AT THE SIDE OF SAID BOOM PIVOT MEANSREMOTE FROM SAID LOAD-SUPPORTING MEANS AND LOCATED A DISTANCE FROM SAIDBOOM PIVOT MEANS GREATER THAN THE DISTANCE BETWEEN THE CONNECTION OFSAID FIRST LINE TO SAID BOOM AND SAID BOOM PIVOT MEANS, AND SAID SECONDLINE BEING LOOPED FROM ITS CONNECTION TO SAID BOOM DOWNWARD AROUND SAIDSHEAVE, AND MEANS OPERABLE TO VARY THE EFFECTIVE LENGTHS OF SAID LINES,FOR TILTING SAID BOOM RELATIVE TO SAID MAST PRINCIPALLY BY VARYING THEEFFECTIVE LENGTH OF SAID SECOND LINE AND FOR SWINGING SAID MAST RELATIVETO SAID BASE PRINCIPALLY BY VARYING THE EFFECTIVE LENGTH OF SAID FIRSTLINE.